Angular 5订阅SwitchMap内部的Observable

Question

I'm trying to subscribe to an inner Observable. Here is what I'm doing:

getDates() {
  if (this.booking.id) {

    this.jobService.findById(this.booking.id)
      .map(job => job[0])
      .switchMap((job) => {
        return job ? this.bookingService.findByPropertyId(job.property.id) : Observable.empty();
      }, (job: Job, bookings: Booking[]) => {
        this.mark_jobs_unavailable(job, bookings);
        return job;
      })
      .subscribe(job => {
        this.bookingJob = job;
      });

  }
}

My code is working fine, The only thing I'm trying to achieve is to subscribe to changes of my Bookings as well. Currently as I'm not sure where should I subscribe to the Observable that I get from bookingService.findByPropertyId , My app does not reflect to changes happening in bookings collection.

Answer 1

为了获得有关预订的更改， bookingService.findByProperyId()必须在发生更改的任何时候（即它可以在一段时间内返回多个值bookingService.findByProperyId()返回可观察的值。

Answer 2

You can try something like this:

this.jobService.findById(this.booking.id)
    .mergeAll() // or .mergeAll().first()
    .switchMap(
        job => this.bookingService.findByPropertyId(job.property.id),
        (job, bookings) => [job, bookings]
    )
    .subscribe(([job, bookings]) => {
        this.bookingJob = job;
        this.mark_jobs_unavailable(job, bookings);
    });

Now you have both job and bookings in the subscribe method